Businesses or other entities having a need for volume printing typically purchase a production printer. A production printer is a high-speed printer used for volume printing, such as 100 pages per minute or more. The production printers are typically continuous-form printers that print on paper or some other printable medium that is stored on large rolls.
A production printer typically includes a localized print controller that controls the overall operation of the printing system, and a print engine (sometimes referred to as an “imaging engine” or as a “marking engine”). The print engine includes one or more printhead assemblies, with each assembly including a printhead controller and a printhead (or array of printheads). An individual printhead includes multiple tiny nozzles (e.g., 360 nozzles per printhead depending on resolution) that are operable to discharge ink as controlled by the printhead controller. The printhead array is formed from multiple printheads that are spaced in series along a particular width so that printing may occur across the width of the medium.
When in operation, the printable medium is passed underneath the printhead arrays while the nozzles of the printheads discharge ink at particular intervals to form pixels on the medium. Some of the media used in inkjet printers is better suited to absorb the ink, while others are not. Thus, a radiant dryer may be installed downstream from the printhead array. The radiant dryer assists in drying the ink on the medium after the medium leaves the printhead array. A typical radiant dryer includes an array of lamps that emit light and heat. The light and heat from the lamps helps to dry the ink as the medium passes through the dryer.
Some production printers are able to print multiple colors, such as CMYK. CMYK is a color model that uses four colors of ink: Cyan, Magenta, Yellow, and Key (black). Key (K) black ink can cause problems when radiant dryers are installed downstream from a printhead array. The black ink absorbs significantly more radiant energy per volume from the dryer, so it dries faster than the other colors. If the black ink dries too fast, it can begin to burn or scorch on the medium while the other colors are not yet dry. This can unfortunately ruin the printed output on the medium, and can even ignite fires within the dryer.